Camera shutter



p 1939- E. G. BURKHARDT 2,172,238

CAMERA SHUTTER Filed May 26, 1937 INVENTOR: \j: BY M ATTORNEYS.

Patented Sept. 5, 1939 PATENT OFFICE- 2,172,238 0mm summit Ernest G, Burkhardt, Rochester, N. Y., assignor to Eastman Kodak Company, Rochester, N. Y., a corporation of New Jersey Applicatlon May 26, 1937, Serial No. 144,850

4Claims.

This invention relates to camera shutters of the blade and cover blind type, and more particularly to a novel shutter stop which limits the return movement of the shutter blade.

An object of the invention is the provision of a shutter stop which not only limits the return movement of the shutter blade, but is movable to position the shutter to permit the taking of either instantaneous or bulb exposures.

Another object of the invention is the provision of such a shutter stop which may be readily and easily moved by the operator to selectively position the shutter for the desired type of exposure.

Still another object is the provision of such a stop which is simple in construction, inexpensive to manufacture, and highly effective in use.

- To these and other ends, the invention resides in certain improvements and combinations of parts all as will hereinafter be more fully described, the novel features being pointed out in the claims at the end of the specifications.

In the drawing:

Fig. l is a front view of a camera of the box type showing the application thereto of a shutter having a bulb stop constructed in accordance with the preferred embodiments of the invention;

Fig. 2 is an enlarged view of a shutter of the blade and cover blind type showing the relation thereto of a bulb stop constructed in accordance with the present invention, the stop being in position to permit the taking of instantaneous or snapshot exposures;

Fig. 3 is a view similar to Fig. 2, but with the stop moved to position the shutter to permit the taking of bulb or time exposures, the shutter trigger being positioned over the exposure aperture to form a light trap therefor; and

Fig. 4 is a view similar to Fig. 3, but with the shutter trigger moved aside to uncover the exposure aperture to make a bulb exposure.

Similar reference numerals throughout the several views indicate the same parts.

The present invention relates to a shutter stop which is adapted to be used in shutters of the blade and cover blind type such as used on box cameras of moderate price. These shutters comprise, in general, a pivoted shutter blade which is arranged to be moved on a pivot in one direction by means of a shutter trigger so as to tension the shutter spring. At a predetermined point, however, the shutter slips oil the trigger, and, under the action of the spring, is quickly returned to its original position. On this return I In order to permit the taking of bulb or time exposures, the present invention provides it shutter stop which may be moved to rotate the shutte'r blade so as to bring the slot therein into registry with the exposure openings in the camera. II

In this position the shutter trigger alone controls the length of exposure.

Referring now to the drawing wherein is shown a shutter of the class described applied to a camera of the box type generally indicated by U the numeral II. The shutter mechanism is mounted on a shutter plate l2 which is secured to the front wall of 'the camera housing in any suitable and well known manner. A shutter blade I3 is mounted for oscillation on a pin or stud H, a

and is formed with an elongated arcuate slot [5 arranged to uncover a circular opening IS in the plate I2 through which an exposure is made. The shutter is operated by means of a shutter trigger l! which is pivotally mounted on a pin it and I0 operated by a lever is which is accessible from the front of the camera, as shown in Fig. 1. The trigger is aflixed to turn with pin l8.

Fig. 2 shows the shutter blade and trigger in their inoperative position to provide a light trap 35 for the opening it. To operate the shutter, the

lever I9 is depressed thus rotating the trigger H in a clockwise direction on the pin II to bring leading edge 20 of the trigger into engagement with a lug 2| struck up from the shutter l3. Upon 40 further depression of the lever I9, the shutter and trigger are rotated about their pivots to the dotted position shown in Fig. 2, the lug' 2| sliding along the upper cam surface 22 of the trigger ll. This movement of the shutter tensions the shutter spring 23.

When, however, the lug 2| reaches the end of the cam surface 22 it slips over the angular corner 24 of the trigger l1, and, under the action of o the spring 23, quickly returns the shutter blade l3 to its original position, as shown in full lines in Fig. 2. On this return stroke of the shutter, the slot 15 thereof momentarily uncovers the opening it to make an instantaneous or snapg;

the slot in the shutter g shot exposure, the trigger l'l position illustrated in Fig. 4.

A shutter stop broadly meral 25, and hereinafter more fully described, may be positioned in the path of the shutter 03 to limit the return movement thereof, as is apparent from the inspection of Figs. 2-4.

A shutter rebound check may also be provided to retard the momentum of the shutter l3 just prior to the engagement thereof with the stop 25. As shown in Fig. 2, this reboimd check may be in the form of a leaf spring 25, one end of which is secured to the shutter it, while the free end thereof is bent, as shown at 2?, to aflord a wiping action as it passes over the upstruck ear 28 to which the shutter spring 231s anchored.

Upon release of the lever it, the trigger ill returns to its original position by reason of the coil spring 29. To facilitate the return of the trigger, the latter is provided with an inclined portion 30 which upon engaging the lug 2i lifts the trigger li so that it will slide over the lu to the position illustrated in Fig. 1. This movement may take place because of the flexibility of the thin sheet metal of which the trigger ill is made. In making an instantaneous exposure, as above described, the time of exposure is controlled entirely by the movement of the slot i5 over the opening it and the tension of spring 28.

In order to make a bulb exposure, it is obviously necessary to uncover the opening it for a period of time longer than is necessary for instantaneous exposures. To accomplish this resuit, the present invention provides a means whereby the shutter it may be rotated on the stud it so as to bring the slot is of the shutter into register with the opening it, as clearly illustrated in Fig. 4, before the trigger is deinthe pressed at all. It is thus apparent that when the shutter and trigger are in the position shown in Fig. 4, the sensitized him will be exposed as long as the lever i9 is held down. so as to maintain the trigger ill in position to uncover the opening it. Such exposures are known to those in the art as bul exposures.

The means for moving the shutter comprises, in the present embodiment, the shutter stop 25 preferably of the shape shown in the drawing. This stop is secured to and rotatable with a pin 3i which extends through and is rotatably mounted in the shutter plate E2 in the front wall of the camera l I. When the stop is in the position shown in Fig. 2, it engages an upstruck ear 32 on the plate 52 and acts merely as a stop to limit the return movement of the shutter 83.

When, however, the pin Si is rotated in a clockwise direction, as viewed in Figs. 2-4, the cam surface 33, on the stop 25, engages a lug 3% formed on an arm 35 integral with the shutter l3 and concentric with the stud M, and rotates the shutter in a counter-clockwise direction to the position shown in Fig. 3, the stop 25 then abutting the ear 28 on the plate l2. In this position, the slot is of the shutter is brought into registry with the opening It. The stop 25 is moved to its different positions by means of a hand lever 35 which is secured to the outer end of the pin Si by means of a screw ill. The lever designated by the nu-' clockwise direction. under the action of the spring 23, untilthe lug 34 engages the surface- 33 of the stop 25, thus limiting the return of the shutter so as to bring the slot l5 thereof into registry with the opening lito uncover the latter. With the shutter in this position, the sensitized film will be exposed as long ,as the trigger is is maintained in the position illustrated in Fi 4; v I H After the desired exposure is made, however, the lever is is released, and the spring 28 returns the trigger to its original position, as shown in Figs. 2 and 3 and above described, thus affording a cover for the opening it. Thus in making bulb exposures, the time of exposure is controlled solely by the trigger ll, while in'snapshots the shutter it controls the length of exposure. The shutter i3 may be easily and quick- 1y returned to the position shown in Fig. 1 by merely moving the lever 36 to rotate the pin ll and the stop 25 in a counter-clockwise direction,

thus moving the cam surface 33 out of engagement with the lug 36, see Fig. 2. The shutter i8 is now free to rotate on a pin i4, under the action oi the spring 23, to move the shutter from the position shown in Fig, 3 to the position shown in Fig. 2 to again permit the taking of instantaneous or snapshot exposures.

It is thus apparent from the above description that the present invention provides a shutter stop which may be moved to one position to rotate the shutter to permit the tamng of a bulb exposure, or is movable to another position to permit the taking of snapshots or instantaneous exposures. In both positions, the stop affords a means for limiting the return movement of the shutter thus accurately positioning the latter so that the desired exposure may be made.

While only one embodiment of the invention has been disclosed, it is to be understood that the inventive idea may be carried out in a number of ways, This application is, therefore, not to be limited to the precise details described, but is intended to cover all variations and modifications thereof falling withinthe spirit of the invention and the scope of the appended claims.

I claim:

1. In a photographic shutter, the combination with an apertured shutter plate, a spring operated shutter pivotally mounted on said plate and movable in one direction to uncover said aperture to make an exposure, a lug on said shutter, a shutter operating trigger for moving said shutter in the opposite direction to tension said shutter, of a pin rotatably mounted on said plate adjacent the pivot point of said shutter, a shutter stop mounted on one end of said pin and positioned in the path of said shutterwhen the latter is moved in said one direction to limit the return movement thereof, a cam surface on said stop arranged to be moved to engage said lug upon rotation of said pin to one position whereby said shutter is shifted to uncover said aperture, said trigger serv-' ing to cover said aperture when said shutter is shifted, means for moving said trigger to uncover said aperture to make a time exposure, said cam being movable upon rotation of the pin to another position to permit said shutter to only momentarily uncover said aperture to make an instantaneous exposure when said trigger is operated, a manual control lever mounted on the other end of said pin to move saidcam to said positions, and means on said plate for limiting the movement of said cam.

2. In a photographic shutter the combination with an apertured plate, a slotted shutter pivotally mounted on. said plate and adapted to be moved to bring said slot into registry with said aperture to make an exposure, of a member rockably mounted on said plate adjacent the pivot point of said shutter and movable relative thereto to engage and move said shutter about its pivot so that said slot uncovers said aperture, a shutter trigger mounted on said plate and arranged to cover said aperture when said shutter is positioned, and means for moving said trigger to uncover said aperture so that said exposure will be controlled by movement of said trigger.

3. In a photographic shutter the combination with an apertured plate, a pivoted slotted shutter mounted on said plate and adapted to be moved to bring said slot into registry with said aperture to make an exposure, a spring operated shutter trigger arranged to engage said shutter to move the latter in one direction and cooperating with the shutter during such movement to cover said aperture, means for moving the shutter in the opposite direction, of a shutter stop pivotally mounted on said plate and arranged to be engaged by said shutter to limit the return movement thereof, means for moving said stop about its pivot to en-,

gage and turn said shutter about its pivot to bring the slot therein into registry with said aperture, and means for moving said trigger to uncover said aperture in order that the trigger will provide the sole means for controlling the length of the exposure.

4.. in a photographic shutter the combination with an apertured plate, a pivoted slotted shutter mounted on said plate and adapted to be moved to bring said slot into registry into said aperture to make an exposure, a spring operated shutter trigger arranged to engage said shutter to move the latter in one direction and cooperating with the shutter during such movement to cover said aperture, means for moving the shutter in the opposite direction, of a shutter stop pivotally mounted on said plate and arranged to be engaged by said shutter to limit the return movement thereof, a cam on said stop, means for rotating said stop to bring said cam into engagement with said shutter to move the latter to uncover said aperture so that said shutter is ineffective in controlling the exposure, and means for moving said trigger to uncover said aperture to make the exposure.

ERNEST G, BURKHARDT. 

